Ventilation fan



FIG. 1 is a perspective view showing a first embodiment of a ventilation fan showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a perspective view showing a second embodiment of a ventilation fan showing our new design;

FIG. 9 is a front elevational view thereof;

FIG. 10 is a rear elevational view thereof;

FIG. 11 is a left side elevational view thereof;

FIG. 12 is a right side elevational view thereof;

FIG. 13 is a top plan view thereof; and,

FIG. 14 is a bottom plan view thereof.

The broken line portions in the drawing views are included to show unclaimed subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a ventilation fan, as shown and described. 